You can't tell where a sledge hammer is likely to break.

You get it in the head like a sledge hammer!

Something like a sledge hammer struck him at the side of the head.

So was the heavy sledge hammer he picked up and took with him.

"We had to hit this with a sledge hammer," he said.

They had no further use for a broken sledge hammer.

It's like you've been struck with a sledge hammer, I'm sure.

My head feels as though it had hit me with a sledge hammer.

"It's like using a sledge hammer to hit a small nail."

The console looked as if it had been smashed open by a sledge hammer.